CISCO CCNA Exam – Q63

Which two protocols are used by bridges and/or switches to prevent loops in a layer 2 network? (Choose two.)

A. 802.1d
B. VTP
C. 802.1q
D. STP
E. SAP

Correct Answers: A, D

Explanation:
This question is to examine the STP protocol.
STP (802.1d) is used to prevent Layer 2 loops.
802.1q is a Frame Relay protocol which belongs to VLAN.
SAP is a concept of the OSI model.

CISCO CCNA Exam – Q62

Which switch would STP choose to become the root bridge in the selection process?

A. 32768: 11-22-33-44-55-66
B. 32768: 22-33-44-55-66-77
C. 32769: 11-22-33-44-55-65
D. 32769: 22-33-44-55-66-78

Correct Answer: A

Explanation:
The root bridge of the spanning tree is the bridge with the smallest (lowest) bridge ID. Each bridge has a configurable priority number and a MAC Address; the bridge ID contains both numbers combined together – Bridge priority + MAC (32768.0200.0000.1111). The Bridge priority default is 32768 and can only be configured in multiples of 4096 (Spanning tree uses the 12 bits extended system ID). To compare two bridge IDs, the priority is compared first, as if looking at a real number anything less than 32768…will become the target of being the root. If two bridges have equal priority then the MAC addresses are compared; for example, if switches A (MAC=0200.0000.1111) and B (MAC=0200.0000.2222) both have a priority of 32768 then switch A will be selected as the root bridge.
In this case, 32768: 11-22-33-44-55-66 would be the bridge because it has a lower priority and MAC address.

CISCO CCNA Exam – Q61

A switch is configured with all ports assigned to VLAN 2 with full duplex FastEthernet to segment existing departmental traffic. What is the effect of adding switch ports to a new VLAN on the switch?

A. More collision domains will be created.
B. IP address utilization will be more efficient.
C. More bandwidth will be required than was needed previously.
D. An additional broadcast domain will be created.

Correct Answer: D

Explanation:
Each VLAN creates its own broadcast domain. Since this is a full duplex switch, each port is a separate collision domain.

CISCO CCNA Exam – Q60

What are three benefits of implementing VLANs? (Choose three.)
A. A higher level of network security can be reached by separating sensitive data traffic from other network traffic.
B. A more efficient use of bandwidth can be achieved allowing many physical groups to use the same network infrastructure.
C. A more efficient use of bandwidth can be achieved allowing many logical networks to use the same network infrastructure.
D. Broadcast storms can be mitigated by increasing the number of broadcast domains, thus reducing their size.
E. Broadcast storms can be mitigated by decreasing the number of broadcast domains, thus increasing their size.
F. VLANs make it easier for IT staff to configure new logical groups, because the VLANs all belong to the same broadcast domain.
G. Port-based VLANs increase switch-port use efficiency, thanks to 802.1Q trunks.

Correct Answer: A, C, D

Explanation:
Benefits of VLANs
VLAN is a network structure which allows users to communicate while in different locations by sharing one multicast domain and a single broadcast. They provide numerous
networking benefits and have become popular in the market. For instance, it helps reduce administrative costs when users are geographically dispersed.
1. Inexpensive
The popularity of VLANs is due to the fact that changes, adds, and moves can be attained simply by making necessary configurations on the VLAN port. Time-consuming, readdressing,
and host reconfigurations is now a thing of the past, because network configuration can be made at ease when need arises.
2. Better management
A VLAN typically solve the scalability issues that exist in a large network by breaking the main domain into several VLAN groups or smaller broadcast configurations, thereby
encourage better control of multicast traffic as well as broadcast domains.
3. Improves network security
High-security can be positioned in different VLAN groups to ensure that non-members cannot receive their broadcasts. On the other hand, a router is added and workgroups
relocated into centralized locations.
4. Enhances performance
A more efficient use of bandwidth can be achieved allowing many logical networks to use the same network infrastructure.
5. Segment multiple networks
VLANs are typically used to achieve multiple purposes. They are popularly used to reduce broadcast traffic. Each VLAN creates a separate, smaller broadcast domain.
6. Better administration
VLANs facilitate grouping of multiple geographical stations. When VLAN users move to another physical location, the network does not have to be configured.

CISCO CCNA Exam – Q59

Which IEEE standard protocol is initiated as a result of successful DTP completion in a switch over Fast Ethernet?

A. 802.3ad
B. 802.1w
C. 802.1D
D. 802.1Q

Correct Answer: D

Explanation:
Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol for negotiating trunking on a link between two devices and for negotiating the type of trunking encapsulation (802.1Q) to be used.

CISCO CCNA Exam – Q58

Which of the following are benefits of VLANs? (Choose three.)

A. They increase the size of collision domains.
B. They allow logical grouping of users by function.
C. They can enhance network security.
D. They increase the size of broadcast domains while decreasing the number of collision domains.
E. They increase the number of broadcast domains while decreasing the size of the broadcast domains.
F. They simplify switch administration.

Correct Answer: B,C,E

Explanation:
When using VLAN the number and size of collision domains remain the same.
VLANs allow to group users by function, not by location or geography.
VLANs help minimize the incorrect configuration of VLANs so it enhances the security of the network.
VLAN increases the size of broadcast domains but does not decrease the number of collision domains.
VLANs increase the number of broadcast domains while decreasing the size of the broadcast domains which increase the utilization of the links. It is also a big advantage of VLAN.
VLANs are useful but they are more complex and need more administration.

CISCO CCNA Exam – Q57

Refer to the exhibit.
CISCO CCNA Exam – Q57
A technician has installed SwitchB and needs to configure it for remote access from the management workstation connected to SwitchA. Which set of commands is required to accomplish this task?

A.
SwitchB(config)# interface FastEthernet 0/1
SwitchB(config-if)# ip address 192.168.8.252 255.255.255.0
SwitchB(config-if)# no shutdown
B.
SwitchB(config)# interface vlan 1
SwitchB(config-if)# ip address 192.168.8.252 255.255.255.0
SwitchB(config-if)# ip default-gateway 192.168.8.254 255.255.255.0
SwitchB(config-if)# no shutdown
C.
SwitchB(config)# ip default-gateway 192.168.8.254
SwitchB(config)# interface vlan 1
SwitchB(config-if)# ip address 192.168.8.252 255.255.255.0
SwitchB(config-if)# no shutdown
D.
SwitchB(config)# ip default-network 192.168.8.254
SwitchB(config)# interface vlan 1
SwitchB(config-if)# ip address 192.168.8.252 255.255.255.0
SwitchB(config-if)# no shutdown
E.
SwitchB(config)# ip route 192.168.8.254 255.255.255.0
SwitchB(config)# interface FastEthernet 0/1
SwitchB(config-if)# ip address 192.168.8.252 255.255.255.0
SwitchB(config-if)# no shutdown

Correct Answer: C

Explanation:
To remote access to SwitchB, it must have a management IP address on a VLAN on that switch. Traditionally, we often use VLAN 1 as the management VLAN (but in fact it is not secure).

In the exhibit, we can recognize that the Management Workstation is in a different subnet from the SwitchB. For intersubnetwork communication to occur, you must configure at least one default gateway. This default gateway is used to forward traffic originating from the switch only, not to forward traffic sent by devices connected to the switch.

CISCO CCNA Exam – Q56

Which two states are the port states when RSTP has converged? (Choose two.)

A. discarding
B. listening
C. learning
D. forwarding
E. disabled

Correct Answers: A, D

Explanation:
There are only three port states left in RSTP that correspond to the three possible operational states. The 802.1D disabled, blocking, and listening states are merged into a unique 802.1w discarding state.

CISCO CCNA Exam – Q56

Reference: http://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cfa.shtml#states

CISCO CCNA Exam – Q55

Which two commands can be used to verify a trunk link configuration status on a given Cisco switch interface? (Choose two.)

A. show interface trunk
B. show interface interface
C. show ip interface brief
D. show interface vlan
E. show interface switchport

Correct Answers: A, E

Explanation:
Example output from these two commands:
SW3#show interface trunk
Port Mode Encapsulation Status Native vlan
Fa0/19 auto n-802.1q trunking 1
http://ExamQuestions.info
Fa0/20 auto n-802.1q trunking 1
Fa0/21 auto n-802.1q trunking 1
Fa0/22 auto n-802.1q trunking 1
Port Vlans allowed on trunk
Fa0/19 1-4094
Fa0/20 1-4094
Fa0/21 1-4094
Fa0/22 1-4094

SW1#show interface fast 0/2 switchport
Name: Fa0/2
Switchport: Enabled
Administrative Mode: dynamic desirable
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of TrunkinG. On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 1 (default)
Voice VLAN: none

CISCO CCNA Exam – Q54

Which command enables RSTP on a switch?

A. spanning-tree uplinkfast
B. spanning-tree mode rapid-pvst
C. spanning-tree backbonefast
D. spanning-tree mode mst

Correct Answer: B

Explanation:
Rapid Spanning Tree Protocol (RSTP) is an enhancement of the original STP 802.1D protocol. The RSTP 802.1w protocol is an IEEE open implementation. Cisco has its own proprietary implementation of RSTP, that includes the benefits of its Per-VLAN spanning tree protocols, called Rapid-PVST+.
To activate the Rapid-PVST+ protocol:
switch(config)#spanning-tree mode rapid-pvst